\frac { 5 . r + 7 } { 2 } - 2 . r + 4 = \frac { 3 . x + 9 } { 4 }
Solve for r
r=\frac{3\left(x-7\right)}{2}
Solve for x
x=\frac{2r}{3}+7
Share
Copied to clipboard
2\left(5r+7\right)-8r+16=3x+9
Multiply both sides of the equation by 4, the least common multiple of 2,4.
10r+14-8r+16=3x+9
Use the distributive property to multiply 2 by 5r+7.
2r+14+16=3x+9
Combine 10r and -8r to get 2r.
2r+30=3x+9
Add 14 and 16 to get 30.
2r=3x+9-30
Subtract 30 from both sides.
2r=3x-21
Subtract 30 from 9 to get -21.
\frac{2r}{2}=\frac{3x-21}{2}
Divide both sides by 2.
r=\frac{3x-21}{2}
Dividing by 2 undoes the multiplication by 2.
2\left(5r+7\right)-8r+16=3x+9
Multiply both sides of the equation by 4, the least common multiple of 2,4.
10r+14-8r+16=3x+9
Use the distributive property to multiply 2 by 5r+7.
2r+14+16=3x+9
Combine 10r and -8r to get 2r.
2r+30=3x+9
Add 14 and 16 to get 30.
3x+9=2r+30
Swap sides so that all variable terms are on the left hand side.
3x=2r+30-9
Subtract 9 from both sides.
3x=2r+21
Subtract 9 from 30 to get 21.
\frac{3x}{3}=\frac{2r+21}{3}
Divide both sides by 3.
x=\frac{2r+21}{3}
Dividing by 3 undoes the multiplication by 3.
x=\frac{2r}{3}+7
Divide 2r+21 by 3.
Examples
Quadratic equation
{ x } ^ { 2 } - 4 x - 5 = 0
Trigonometry
4 \sin \theta \cos \theta = 2 \sin \theta
Linear equation
y = 3x + 4
Arithmetic
699 * 533
Matrix
\left[ \begin{array} { l l } { 2 } & { 3 } \\ { 5 } & { 4 } \end{array} \right] \left[ \begin{array} { l l l } { 2 } & { 0 } & { 3 } \\ { -1 } & { 1 } & { 5 } \end{array} \right]
Simultaneous equation
\left. \begin{cases} { 8x+2y = 46 } \\ { 7x+3y = 47 } \end{cases} \right.
Differentiation
\frac { d } { d x } \frac { ( 3 x ^ { 2 } - 2 ) } { ( x - 5 ) }
Integration
\int _ { 0 } ^ { 1 } x e ^ { - x ^ { 2 } } d x
Limits
\lim _{x \rightarrow-3} \frac{x^{2}-9}{x^{2}+2 x-3}